From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:40651 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752649Ab3GZTMs convert rfc822-to-8bit (ORCPT ); Fri, 26 Jul 2013 15:12:48 -0400 From: Laurent Pinchart To: Jakub Piotr =?utf-8?B?Q8WCYXBh?= Cc: Tomi Valkeinen , linux-media Subject: Re: [omapdss] fault in dispc_write_irqenable [was: Re: [omap3isp] xclk deadlock] Date: Fri, 26 Jul 2013 21:13:44 +0200 Message-ID: <1478956.6pKyoNTpv1@avalon> In-Reply-To: <51F2C7CB.9040806@zenburn.net> References: <51D37796.2000601@zenburn.net> <2345948.CFuZYJZjKT@avalon> <51F2C7CB.9040806@zenburn.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="utf-8" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Jakub, On Friday 26 July 2013 21:02:35 Jakub Piotr Cłapa wrote: > On 26.07.13 17:52, Laurent Pinchart wrote: > >>> Using omapfb, or...? I hope not > >>> omap_vout, because that's rather unmaintained =). > >> > >> Laurent's live application is using the V4L2 API for video output (to > >> get free YUV conversion and DMA) so I guess this unfortunatelly counts > >> as using omap_vout. Are there any alternatives I should look into? IIUC > >> to use omapfb I would need to manually copy RGB data into the > >> framebuffer on each frame. > > > > It should be possible to port the live application to use DRM/KMS with > > omapdrm for the display side, without requiring any memory copy. That's > > somewhere on my TODO list, but I won't have time to work on that before > > way too long. > I could look into it myself but is there any documentation on omapdrm? > > From what I found libdrm should probably be used but information about it's > API is really scarce: > https://dvdhrm.wordpress.com/2012/09/13/linux-drm-mode-setting-api/ > http://dvdhrm.wordpress.com/2012/12/21/advanced-drm-mode-setting-api/ > http://virtuousgeek.org/blog/index.php/jbarnes/2011/10/31/writing_stanalone_ > programs_with_egl_and_ > > The last one seems focused on OpenGL so I don't think it applies. > > Are there any good sources to learn about this? Or maybe some pointers on > where to start with reading source code? http://events.linuxfoundation.org/sites/events/files/lcjpcojp13_pinchart.pdf A bit of shameless self-advertising :-) It would have been clearer with the video, but it seems the talk hasn't been recorded :-/ There's also http://www.youtube.com/watch?v=Ja8fM7rTae4 that mostly focuses on the kernel side but starts with explanations of the key KMS concepts. As far as KMS is concerned, libdrm is mostly a wrapper, so any documentation on the KMS ioctls can help too. -- Regards, Laurent Pinchart